As gardeners, Brian and I have always had a complicated relationship with weeds. Some, like mugwort, are our sworn enemies; others, like purple deadnettles, we just try to coexist with. Clover, a plant that many homeowners consider a weed, we actively encourage to grow in our yard, because it competes with the truly obnoxious weeds and enriches the soil with nitrogen. But the most confusing "weeds" of all are the ones that are actually garden crops—veggies that we've cultivated on purpose—that pop up in places where we haven't planted them. Should do we treat these as weeds to be removed, or as annexes to our main garden space?
The answer depends on several factors, such as how much in the way the plants are and how good they taste. For example, I have decided to insist on removing all volunteer tomato plants that pop up in our side yard, because (a) the sprawling vines take over the entire yard, making it nearly impassible, and (b) since they're mostly the offspring of hybrid tomatoes, they don't breed true—so even particularly tasty parent varieties, like Sun Golds, end up producing unremarkable-tasting fruit. However, the large butternut squash vine that twined its way through the side yard in 2010 was allowed to stay, because it provided us with a generous crop of our favorite squash. Contrariwise, the volunteer tomato plants that have proliferated this year on the far side of our garden plot have also been tolerated, because although their fruits aren't great, there isn't really anything more important growing there.
Often, the place where volunteer plants are most of a nuisance is in the garden itself. Last year, for instance, when our Sun Golds produced so heavily that we couldn't keep up with the job of harvesting them, the tomatoes that dropped off the vines into the garden beds produced dozens of tiny seedlings that we had to yank quickly before they turned into huge, sprawling vines and choked out all our lettuce. The year before that, when one of our dill plants went to seed, dill ended up being one of the most prolific "weeds" in our garden (though one that we could usually pull up and eat, rather than just pull up and throw away).
Up until this year, however, the problem of weed-veggies in the garden had been confined to the beds. Now, for the first time, we're having vegetables pop up in the paths. Our new garden paths have, alas, not proven quite so impervious to weeds as we'd hoped they would be; the relentless mugwort has repeatedly managed to poke through the landscape cloth and the layer of stone dust over it, and other weeds have snaked their way under the edges of the landscape cloth to proliferate around the boundaries of the beds. But this week is the first time we've spotted bits of green poking their way through the weed barrier that turned out, on close inspection, to be none other than arugula.
Nor is the arugula invasion (which, by the way, would be a great name for an alternative band) confined to the garden. We've seen volunteer arugula plants in several other places around the yard as well. There's a good-sized patch of it in the side yard, right around the base of the compost bin, and some of it appears to be growing up through the cracks in the driveway. It's actually kind of ironic, because the arugula we actually planted in the garden this year didn't yield well at all, and now here it is appearing in all these places where it's never been grown before.
Our best guess as to how it happened is that after our arugula plants bolted, several of them got pulled out and mixed in with a big pile of woody weeds that we stored next to the bin, waiting for them to dry out so we could strip the branches of leaves before bundling them. It must have scattered some seeds there, resulting in the present crop of arugula, which looks far healthier than the patch we actually planted this spring ever did. Then, once the bundles of brush got moved to the driveway to wait for bulk trash pickup, the arugula continued to drop seeds, sowing a new generation of plants through the cracks in the concrete.
So, bizarrely, a veggie that we completely failed to grow a decent crop of on purpose this spring is now coming up all over the place this fall. I've already picked two big plants from the garden paths, as well as one from the bed itself, and that bunch alone has probably doubled the size of the harvest we got in the spring. Add to that what's currently left in the bed, and in the driveway, and in front of the compost bin, and arugula may end up being one of this year's most profitable garden crops, completely by chance.
Like I've said before: a gardener's life is full of surprises.